Light-emitting diode (LED) light sources may be used as replacements for conventional incandescent lamps. LED light sources may include a plurality of light-emitting diodes mounted on a single structure and provided in a suitable housing. The LEDs may be coupled in series and/or in parallel.
LED light sources may be more efficient and may provide longer operational lives as compared to incandescent lamps. In order to illuminate properly, an LED driver may be coupled between an alternating-current (AC) power source and the LED light source for regulating the operating current and operating voltage supplied to the LED light source. For example, the LED driver may be integrated into a base of a screw-in LED bulb. Additionally, in order to provide an end user the ability to control the intensity of the LED light sources, a load control device, such as a dimmer switch, for example, may be utilized to control the LED driver. The load control device may provide a control signal to the LED driver.
LED drivers may exhibit different operating characteristics, such as impedance characteristics, for example, depending on the manufacturer and/or model of the LED driver. Different impedance characteristics may require different types of phase control signals to be provided by the load control device in order to control the LED driver and to dim the LED light source properly.
Typical LED drivers are characterized by both capacitive and inductive impedance. In order to properly control an LED driver having a predominately capacitive impedance, the load control device should provide a reverse phase control signal to the LED driver. In order to properly control an LED driver having a predominately inductive impedance, the load control device should provide a forward phase control signal to the LED driver.